Why can't I explicitly return void from a method?

Question

void run() {
    ...
    if (done) return cancel();
    ...
}

where cancel() return void. This won\'t compile... and I ca

Answer 1

A return statement with an expression returns the value of that expression. The type of cancel() is a void expression - it doesn't have a value.

Logically you want to execute cancel(), and then return - so that's what you have to say. The two actions (calling cancel() and then returning) are logically distinct.

Now Java could have a sort of "unit" type instead of void - but that would affect rather more than just return values.